src/mesa/pipe/softpipe/sp_quad_alpha_test.c

   1
   2 /**
   3  * quad alpha test
   4  */
   5
   6 #include "glheader.h"
   7 #include "imports.h"
   8 #include "sp_context.h"
   9 #include "sp_headers.h"
  10 #include "sp_quad.h"
  11 #include "pipe/p_defines.h"
  12
  13
  14 static void
  15 alpha_test_quad(struct quad_stage *qs, struct quad_header *quad)
  16 {
  17    struct softpipe_context *softpipe = qs->softpipe;
  18    const GLfloat ref = softpipe->alpha_test.ref;
  19    GLuint passMask = 0x0, j;
  20
  21    switch (softpipe->alpha_test.func) {
  22    case PIPE_FUNC_NEVER:
  23       quad->mask = 0x0;
  24       break;
  25    case PIPE_FUNC_LESS:
  26       /*
  27        * If mask were an array [4] we could do this SIMD-style:
  28        * passMask = (quad->outputs.color[3] <= vec4(ref));
  29        */
  30       for (j = 0; j < QUAD_SIZE; j++) {
  31          if (quad->outputs.color[3][j] < ref) {
  32             passMask |= (1 << j);
  33          }
  34       }
  35       break;
  36    case PIPE_FUNC_EQUAL:
  37       for (j = 0; j < QUAD_SIZE; j++) {
  38          if (quad->outputs.color[3][j] == ref) {
  39             passMask |= (1 << j);
  40          }
  41       }
  42       break;
  43    case PIPE_FUNC_LEQUAL:
  44       for (j = 0; j < QUAD_SIZE; j++) {
  45          if (quad->outputs.color[3][j] <= ref) {
  46             passMask |= (1 << j);
  47          }
  48       }
  49       break;
  50    case PIPE_FUNC_GREATER:
  51       for (j = 0; j < QUAD_SIZE; j++) {
  52          if (quad->outputs.color[3][j] > ref) {
  53             passMask |= (1 << j);
  54          }
  55       }
  56       break;
  57    case PIPE_FUNC_NOTEQUAL:
  58       for (j = 0; j < QUAD_SIZE; j++) {
  59          if (quad->outputs.color[3][j] != ref) {
  60             passMask |= (1 << j);
  61          }
  62       }
  63       break;
  64    case PIPE_FUNC_GEQUAL:
  65       for (j = 0; j < QUAD_SIZE; j++) {
  66          if (quad->outputs.color[3][j] >= ref) {
  67             passMask |= (1 << j);
  68          }
  69       }
  70       break;
  71    case PIPE_FUNC_ALWAYS:
  72       passMask = MASK_ALL;
  73       break;
  74    default:
  75       abort();
  76    }
  77
  78    quad->mask &= passMask;
  79
  80    if (quad->mask)
  81       qs->next->run(qs->next, quad);
  82 }
  83
  84
  85 static void alpha_test_begin(struct quad_stage *qs)
  86 {
  87    if (qs->next)
  88       qs->next->begin(qs->next);
  89 }
  90
  91
  92 struct quad_stage *
  93 sp_quad_alpha_test_stage( struct softpipe_context *softpipe )
  94 {
  95    struct quad_stage *stage = CALLOC_STRUCT(quad_stage);
  96
  97    stage->softpipe = softpipe;
  98    stage->begin = alpha_test_begin;
  99    stage->run = alpha_test_quad;
 100
 101    return stage;
 102 }